Krasnaya Polyana, Russia — Marie Marchand-Arvier escaped a crash into the safety nets during the women's downhill unharmed on Wednesday but the incident highlighted yet again the dangers of Olympic winter sports.

Tina Weirather had to withdraw from the downhill over a training injury while Lindsey Vonn didn't even make it to the Sochi Games over a knee injury she first suffered at the 2013 world championships.

High-speed downhills have always been risky affairs in which athletes throw themselves down steep slopes with more than 100kph in skintight suits, protected only by a back-padding and a helmet.

Snowboarders and freestylers saw controversies around the safety of their courses after several incidents, and even cross-country skiers were not safe from falls on slopes where they have reached more than 70kph.

The Sanki Sliding Centre meanwhile has been a safe place so far which is good news as Wednesday marked the fourth anniversary of the death of Georgian slider Nodar Kumaritashvili in training at the Vancouver 2010 Games.

Russian organizers and the involved federations learned their lesson, as the track is considered challenging but without taking it to the same extremes as the course in Whistler 2010. It even features three uphill sections to reduce the speed.

IOC spokesman Mark Adams reiterated Wednesday that safety is "not an IOC issue, first and foremost, it is for the federation.

"It is always an issue; it always will be in winter sports. But I think it's pretty well handled. I think the federation are doing a good job and I think the athletes are pretty happy."

Another death is the least the Olympics can afford, and the safety debate was on for good again when fancied Norwegian slopstyler Torstein Horgmo broke his collarbone and Finland's Merika Enne was another casualty even before the action started.

American superstar Shaun White said the course at Rosa Khutor Extreme Park was "intimidating," before pulling out, while Canadian gold medal contender Mark McMorris, who competed with a rib fracture from the recent X Games, dismissed it as "not dangerous at all."

Kaya Turski was another prominent crash victim and White almost succumbed to the treacherous halfpipe as well. He remained on his feet but his dream of a third straight gold was over.

That went instead to Swiss Iouri Podladtchikov, whose best trick is the so-called yolo - short for "you live only once."

That fits the somewhat care-free attitude the young generation stands for - a key audience Olympians are vying for in order to keep the Games attractive.

However it's a thin line between the heroics of Podladtchikov and the cracked helmet of Czech Sarka Pancochova from a slopestyle crash, from which she luckily walked away unharmed.

The late Sarah Burke, who died in a training crash two years, is just one reminder that these so-called "fun sports" can be deadly affairs.

Ski-jumping is almost as risky, with German medal contender Severin Freund tumbling down the hill after cutting an edge on landing in the normal hill competition.

And Austrian Thomas Morgenstern is back in action less than four weeks after being in intensive care with head and lung injuries following a bad crash on the massive flying hill in Bad Mitterndorf.

"Of course there was some tension ahead of the first jump, but as soon as I was in the in-run the feeling was back," Morgenstern said.

That is the best way to avoid a trauma, or, as Austrian downhiller Klaus Kroell recently put it: "Fear only leads to mistakes."